Switch



Nov. 4, 1941.'

n E. s. CORNELL SWITCH 6 Sheets-Sheet 1 Filed June 5, 1940 6Sheets-Sheet 2 Nov. 4, 1941. E. s. CORNELL SWITCH Filed June 5, 1940ffwenfor.- [has S. CorneL Nov. 4, i941. E. s. CORNELL 2,261,843

SWITCH Filed June 5, 1940 6 Sheets-Sheet 5 Nov. 4, 1941. E. s. CORNELLSWITCH s sheets-sheet 4 Filed June 5, 1940 Carney? @5W Nov. 4 1941. E.s. coRNELl.

SWITCH 6 Sheeis-Sheet 5 Filed June 5, 1940 3 Cofwe Nov. 4, 19411, E. S.CORNELL SWITCH Filed June 5, 1940 6 Sheets-Sheet 6 has 5. 60H26@ am, MWI ,throughout the whole areas.

Patented Nov. 4, 1941 SWITCH Elias S. Cornell, Evanston,

Delta-Star Electric Company,

corporation of Illinois Application June 5, 1940, Serial No. 338,860

` 27 Claims. The present invention relates to electric switches, andparticularly to disconnect switches for use under high currentconditions.

Switches of this type are ordinarily not used for breaking orinterrupting current iow in a circuit, since they are not designed towithstand the eiects of the arcs formed by breaking a circuit. Ratherthey are used to provide a definite break in the circuit after thecircuit has been opened by other means such as a circuit breaker.

Due to the peculiar construction of disconnect switches it is arecognized dimculty in connection with them to secure good electricalcontact. To secure good electrical engagement the contacts must be underconsiderable pressure, but when they are under pressure it is difficultto open and close the switch. If the contacts are made to iit loosely inan effort to provide for easy opening and closing, secure electricalengagement is sacriced.

I have overcome this difliculty in a novel manner by the inventionherein disclosed. The device of my invention comprises a simple meansfor providing easy opening and closing operations, and when the switchis closed the contacts will be in good electrical engagement.

I have found that a high pressure contact in a localized region betweenthe contacting surfaces will produce good results in carrying currentwith little loss in efficiency even when the region of contact is lessin normal current carrying capacity than the conductors which areconnected. It has been found impracticable to attempt to attain rmengagement between large areas because the total force necessary to doso is much greater than that necessary for small areas, hence the use ofhigh pressure, small-area contacts. Also in the case of large-areacontacts inaccuracies in alignment prevent engagement Another objectionto large-area contacts is that, when their surfaces become uneven andweather-beaten, rm engagement is next to impossible, but when the areasof contact are small and subjected to great pressure the bodies of thecontacts are made to engage, despite their uneven surfaces.

I have developed a device which embodies the advantageous featuresmentioned above and overcomes the objections mentioned. By a simplemovement of the operating mechanism the switch can be closed with theswitch blades passing freely over the stationary contacts, and bycontinuing the movement of the operating mechanism the contacts arebrought under pressure. Conversely, in the opening operation, on theinitial movement of the operating mechanism, the pressure on thecontacts is released and continued movement will open the switch.

As one feature of my invention I employ multiple current paths which addto the current Ill., assignor to The Chicago, Ill., a

carrying capacity of the switch, and the single operating mechanism ofthe switch is designed to operate the plurality of switch blades in thesame manner in which it operates a single blade.

In the preferred form of the invention, I propose to establish thepressure on the contacts by means of a cam and lever arrangement. 'Ihecam surface is of small inclination, by means of which fact a greatpressure can be exerted on the contacts.

An object of my invention is to provide for applying and releasingcontact pressure between separable switch members respectively after andbefore movement thereat to and from the switch closed position in a newand improved manner.

Another object of my invention is to provide for simultaneously applyingpressure to urge each of a pair of switch members toward the other intocontact engagement with a switch member therebetween and forsimultaneously releasing the switch members from the contact engagementwith the application and release of contact pressure being effectedrespectively, subsequently and prior to relative movement of said switchmembers to and from the switch closed position.

Another object of my invention, in an alternate form, is to provide formaintaining one end of a pair of switch members in constant contactengagement with a stationary switch member therebetween, while bringingthe other end of the pair of switch members into and out of contactengagement with the other stationary switch member.

Other objects and advantages will appear to those skilled in the art onreference to the following detailed description taken in conjunctionwith the accompanying drawings, in which:

Figure 1 is a side elevational view of one form of my invention;

1 Figure 2 is a bottom view of the device shown in Figure l;

Figures 3 and 4 are similar to Figure 1 showing the operating parts indifferent positions;

Figure 5 is a side elevational view of another form of my device;

Figure 6 is a top view of the device shown in Figure 5;

Figures 7 and 8 are views similar to Figures 5 and 6 respectively,showing the operating parts in different positions;

vFigure 9 is a view similar to Figures 5 and 'l showing the switch inpartially open position;

Figure 10 is an enlarged developed view of the cam member of Figure 1taken approximately on the line lll- I0 of Figure 1;

Figure 11 is an enlarged developed view of the cam member of Figure 5taken approximately on the line l l-Il of Figure 5;

Figure 12 is a side elevational view of a modied form of my invention;

Referring now in detail to the drawings, I have' shown in Figures 1 to4,inclusive,one form of disconnect switch which comprises two conductinglines or current paths,atype often found advisable in use with extremelyhigh currents, the plurality of paths providing greater current carryingcapacity and lessening the likelihood of overheating.

Each current path of the switch comprises conductor bars I2 and I4terminating in stationary contacts I2 and I4 respectively, and a contactbar indicated generally by the reference numeral I which is operable toopen and closed position of engagement between the conductor bars. Theconstruction of the two current paths is similar and a description ofone may be duplicated for the other. The two conductor bars I2 areconnected to a single line, as are the two conductor bars I4, and thetwo contact bars I5 are operable in unison into and out of engagementwith the respective conductor bars.

A frame, indicated bythe numeral I6, is bolted or otherwise suitablysecured between the bars I2. Between the bars I4 is a bar support I1,secured thereto by bolts or other suitable means by which the switch asa whole may be supported.

Each of the contact bars is made up of two separate switch blades, I9and 2D, one on either side of each of the conductor bars I2 and I4, andthe two are adapted to move as a unit into and out of engagement withthe conductor bars. In the preferred embodiment the contact bars I5 arepivoted to rotate freely on a shaft I8 which is supported by frame I6and conductor bars I2 and which in turn supports switch operatingmechanism to be described later. At each end of each of the switchblades I9 and 26, is an elongated indented area 2I, extendingtransversely of the blade and stamped in the outer surface thereof. Bythis stamping operation a projection 22 is formed on the inner side ofthe blade opposite the indented area. It will be seen that the locationof these projections 22 is such that they will engage the conductor barsI2 and I4 when thc switch is closed.

At each end of the contact bar I5 is a pair of leaf springs 24, 24 and25, 25', the springs of each pair being mounted on opposite sides of theswitch blades I9 and 26. Each spring member in its preferred form isbuilt up of a plurality of leaves; this adds to the strength of thespring and enables it to withstand the pressureunder which it is put,but it is to be understood that a single leaf may be employed if sodesired. Spring clamps 29 are positioned over the springs and areprovided with down-turned flanges 35 to hold the springs againstdisplacement. The spring assembly is then held in place by studs 21Vwhich pass loosely through openings in the` switch blades I9 and 26,and through the springs and spring clamps. The springs can thus beactuated without any binding effect between studs 21 and the switchblades. The springs 2'4, 24 and 25, 25 are turned inwardly at ytheirouterends as indicated at 3| to t into the indented areas 2 I Thesprings 24, 24 and 25,25 and the switch blades I9 and 20, are eachslotted at their outer ends as shown at 23. This feature adds to theflexibility of both the springs and the switch blades and aids insecuring engagement between the contacts of the switch.

A rotatable cam member 32 is disposed between the switch blades I9 and20 and is pivoted to rotate freely on pin 34 carried by the switchblades. The cam member 32 is in the form of a disc and is generallycircular in formation and provided vwith a lever 35 for operating it.The cam member 32 is provided with four cam surfaces 36, 36 and 31, 31which are arcuate in shape with their center of curvature at `the centerof the cam member and disposed about the periphery of the cam member.Cam surfaces 36 and 36' are disposed on opposite sides of the cam member32 directly opposite to each other, as are the two surfaces 31 and 31',and the surfaces 36, 36 are disposed diametrically opposite lthesurfaces 31, 31. Balls 39 are positioned between the cam surfaces 36, 36and 31, 31 and their corresponding springs, 24, 24 and 25, 25. Theseballs are held in place in openings 40 in the switch blades I9 and 26and act as thrust members between the lcam surfaces and the springs,

Reference is here directed to Figure 10 which shows to best advantagethe shape of the cam member 32. When the cam member is rotated clockwisethe ball thrust members 39 ride up the cam surfaces and onto the widenedportion 4| of the cam member. This action 4spreads the springs 24, 24and 25, 25', the reaction of each caused by the thrust being expended onits corresponding spring through the spring clamps 29 and studs 21,causing the ends 3I of the springs to be forced inwardly and bias theswitch blades into high pressure engagement with the conductor bars I2and I4; and of course when the action is reversed, i. e., the cam member32 rotated counterclockwise, the thrust members 39 ride down onto thenarrow portion 42 of the cam member releasing the pressure on thesprings. Due to the position 0f the cam surfaces 36, 36 and 31, 31', theaction on all the springs is simultaneous, i. e., pressure is exerted onall together, and it is released on all together.

The frame I6 is in the form of a U-shaped bracket, indicated at 44,which is bolted at to the conductor bars I 2 and is provided with a web43 extending between the arms thereof. Mounted on the bracket 44 are twolinks 49 and 50 pivoted at 5I and 52 respectively. A third link 54 ismounted on the two links 49 and 56 at points and 56 respectively, and isconnected to the lever 35 of the cam member 32 at 51. The link 54 isprovided with downwardly extending lugs 59 to whichl is connected aconnecting rod 60 by means of a universal joint 6I. The other end of theconnecting rod 60 is connected through a universal joint 62 to a crankarm 64 attached to a shaft 65. The shaft 65 is mounted in a ball bearing66, or any other suitable bearing, supported by the web 46 and isadapted to be operated by any suitable power or hand opera-tingmechanism.

Operation of the switch is best shown in Figures 3 and 4. Rotation ofthe operating shaft 65 will swing the crank arm 64 which, through theconnecting rod 60, will actuate the link 54 thereby operating the cammember 32 and ultimately the switch itself. The link 54 is designed sothat in its movement from the left to thev right, as shown in Figure 3,it will first rotate the cam member 32 in a counterclockwise directionto release the pressure on the springs without moving the switch bladesI9 and 20, after which continued movement of the link 54 will swing theblades about their pivot on the shaft I8, to the position shown inFigure 4. The arcs through which the links 49 and 59 vswing areindicated at 49 and 50 respectively, and the arc through which the lever35 of the cam member 32 swings in its initial opening movement isindicated at 35'. 'I'he link 59 is longer than the link 49, and due tothis fact the third link 54 is subjected to a compound movement whilethe links 49 and 59 have a simple rotary movement. As the link 54 ismoved from the left to the right (Figure 3) the links 49 and 59 arerotated counterclockwise, and, practically speaking, they establish aparallel movement, with the effect that the initial movement of the link54 is substantially rectilinear, This action enables initial actuationof the cam member 32 without exerting any force on the switch blades inone direction or the other. Obviously the point of connection 51 betweenthe link 54 and the lever 35 must move precisely in the path of the are35' to avoid any movement of the switch blades during operation of -thecam member 32. This is brought about by the relative lengths of thelinks 49 and 59. Since these two links are of different lengths, theyguide the third link 54 so that the point 51 moves in the path of thearc 35' to substantially the position shown in Figure 3. Thismodification of the movement of the link is the only variation from itsrectilinear movement, The usual play present in such connections isample to provide for inaccuracies encountered in practical operations ofthe device. With the cam member 32 in the position shown in Figure 3 thethrust members 39 have ridden down the cam surfaces, releasing thepressure on the springs 24, 24' and 25, 25. Although the switch is hereshown in closed position, the pressure on the switch blades is releasedand the switch can be easily opened. Continued movement of the link 54from the left to the right (as viewed in Figure 3) will swing the links49 and 50 further in a counterclockwise direction until they reach theirpositions shown in Figure 4. As the pivot point 56 of the link 50approaches its position shown in this gure it becomes virtually a xedpivot for the link 54 causing the latter to act as a lever about thispoint and thereby open the switch,

It is, of course, obvious that the reverse of this action takes place inthe closing operation of the switch. In the initial closing movement thelink 54, acting as a lever, pivots in a clockwise direction swinging theswitch to closed position when the link 54 is in the position shown inFigure 3. Thereafter movement of the link to the left (as viewed in thisfigure) rotates the cam member 32 in a clockwise direction therebybringing the switch blades into high pressure engagement with theconductor bars, without then exerting any force of translation on theswitch blades in one direction or the other.

A modied form of my invention is shown in Figures 5 to 9, inclusive. Inthis form is shown a single conductor or current path which comprisesconductor bars 19 and 1I rigidly mounted on insulator stacks 12 and 13,and terminating in stationary contacts 19' and 1|', A movable contactbar indicated generally by the reference numeral 15 and comprising twoblades 16 and 11 constitutes the switching element for bridging theconductor bars. In the preferred form the blades 16 and 11 are pivotedfor free rotation on a shaft 18 supported by the conductor bar 19. Theconductor bars 19 and 1I are secured to their respective insulatorstacks by means of brackets 19 and 89 fittedl over the bottom edges ofthe conductor bars.

The device of this form is essentially the same asthe previousembodiment except that this is a single conductor switch, and it employsa different form of operating mechanism.

The two switch blades 16 and 11 are positioned one on either side ofeach of the stationary contacts 10 and 1I', and the blades at each endthereof are provided with elongated indentations 8 I, formed by punchingor any other desired method, The indentations are formed on the outersurfaces of the switch blades, and result in projections 82 of the samegeneral configuration on the inner surfaces of the blades which areadapted to engage the stationary contacts.

As in the previous embodiment, a number of springs are employed forbringing the switch blades into engagement with the stationary contacts.At each end of the contact bar is a pair of springs, each springoperable to engage one end of one of the switch blades 16 and 11.Springs 84, 84 are .positioned on opposite sides of the switch bladesand are adapted to bring the ends of the switch blades into highpressure engagement with the stationary contact 19', and the springs 85,85 are also positioned on opposite sides of the switch blades, and areadapted to bring the ends of the switch blades into high pressureengagement with the stationary contact 1 I The pair of springs 84, 84are held in place by spring clamps 86, and a stud 81` passing looselythrough the switch blades and the springs and clamps. The pair ofsprings 85, 85 are held in place by a similar arrangement, butl the stud89 in this instance also serves as a support for an arm 99. At the outerend of the springs are inturned portions 9| which are adapted to engagein the indentations 8 I.

The springs 84, 84 and 85, 85 employed in this embodiment of the deviceare in the form of single leaves, but it is to be understood that anyother form of spring may be used, as for instance, the multiple leafspring of the previous embodiment. Both of these springs and thecorresponding springs of the previous embodiment being actually leversas well as springs may also be referred to as levers. l

The arm 99 is positioned between the switch blades 16 and 11 and isprovided with an extension 92 for pivotally mounting it on the stud Thearm 99 is of generally arcuate shape with the portion 94 which extendsout from the switch blades serving as a handle for operating the switchbeing provided with an opening 95 by which it can be engaged by a switchhook. The

' lower end 96 of the arm 90 is positioned between the switch blades andis provided with double cam surfaces |99 and |99. Balls, or thrustmembers, 91 are held in place in openings 99 in the switch blades andare positioned between the inner ends of the springs 84, 84 and 85, 85and the lower end of the arm 90. Reference may be had to Figure 11 for aview of the shape of the cam surface. With the arm 99 in the positionshown in Figure 5 the thrust members 91 will be next to the narrowportion IOI. To operate the springs 84, 84 and 85, 85', the arm 99 isrotated in a counterclockwise direction to the lposition shown in Figure7, during which operation the thrust members 9'1 will ride up on the camsurfaces |99 and |99 to the widened portion of the arm 99. The result-will be to spread the thrust members 91 and the inner ends of thesprings whereby the outer ends of the springs will be biased inwardlybringing the switch blades into high pressure engagement with thestationary contacts. This action of the springs is the same as that ofthe .springs of the previous embodiment, including thefeature that whenthe springs are operated the reaction of each spring caused by .thethrust of the thrust member 91 is eX- pended on the spring on theopposite side of the contact bar through its respective spring clamp 86and stud (81 or 89). The loose relation between thestuds 81 and 80 andthe switch blades 1.6 and 1.1 eliminates any binding eiect between them.

It will be noted that in this embodiment there are only two thrustmembers 91 as distinguished from four in the previous embodiment, onethrust member arranged to operate both springs on one side of thecontact bar 15.

A locking dog |04 is pivoted at |05 between the switch blades 16 and 11and is adapted to engage a lug extending downwardly from the extensionv92 on the arm 00. Also positioned between the switch blades is a coilspring |01 supported at |09, one end of which .is held against movementby a pin IIO, and the other end of which bears against the locking dogbiasing it in a counterclockwise direction into locking engagement withthe lug |06. A stop I II supported in a member II2 mounted on theinsulator stack 13 is positioned so that when the switch is closed thelocking dog |04 will engage the stop which will rotate the locking dogclockwise out of engagement with the lug |06.

lOperation of the switch is performed by actuation of the arm 80. Figure'1 shows the switch in closed position with the springs 84, 84' and 85,85 biasing the switch blades into high pressure engagement with thestationary contacts. When it is desired to open the switch the arm 80 isrotated clockwise until the stop II4 on the arm engages the top of thecontact bar 15. By this movement the pressure on the springs 84, 84 and85, 85 is released and the switch can be opened easily. Continued forceexerted on the arm will open the switch. When the switch is in openposition the locking dog |04 is in locking engagement with the lug |06locking the arm 90 in the position shown in Figure 9. The switch canthen be closed by a reversal of force on the arm 00. When the switchreaches its closed position the locking dog |04 is engaged by the stopwhich releases it from engagement with the lug |06, after which the arm90 may be rotated to the position shown in Figure '1 by continuation ofthe closing movement whereby the springs 84, 85 `and 85, 85 are actuatedbringing the switch blades into high pressure engagement with thestationary contacts.

The projections 22 on the switch blades of the iirst embodiment, and theprojections 82 on the switch blades of the second embodiment whichconstitute the areas of contact between the switch blades and thestationary contacts are substantially more than mere linev contacts. Thecurvature of their surfaces is small and consequently the area ofcontact is of considerable lateral extent. However, these contact areasare small compared with the total area of the stationary contacts andthe ends of the switch blades and it can be readily seen that minormisalignments will not interfere with secure electrical contact.Notwithstanding the small areas of these contacts, the pressure to whichthey are subjected enhances their current carrying capacity so that itis not materially less than that of the conductor bars.

Figures 12 and 14, respectively, show two modications of the inventionsimilar to the two forms shown and described previously, but each with adifferent kind of contact at the hinge end of the switch blade. In eachof the present two forms the hinge end of the switch blade is held underconstant pressure in engagement with the corresponding stationarycontact. In so far as the present forms of the invention contain partscommon with the previous forms, the same reference numerals will applyto both, and the description ofthose parts and the operation thereofwill suflice for both.

Referring to Figure 12. the usual contact bar i5 is pivoted on theconductor bar I2 at |20, and consists vof two switch blades I9 and 20,one positioned on either side of the conductor bar i2. The contact areasbetween the switch blades I9 and 20 and the conductor bar I2 are in theform of annular indentations I2I in the outer surface of the switchblades around the pivot point |20. These indentations result inprojections |22 (Figure 13) on the inner surfaces of the switch bladeswhich engage the conductor bar I2. Spring washers |24 with inturnedflanges E25 t into the indented areas |2I and are adapted thereby tobring the contact areas |22 into pressure engagement with the associatedconductor bar I2 by means of nuts |21 threaded on studs |25 passingthrough aligned openings in the conductor bar, switch blades and springwashers. Reference may be had to Figure 13 which shows to good advantagehow the various partsk are fitted together. This form of switch issimilar to that shown in Figure 1, and, although not shown in Figure 13,includes two current paths, each with conductor bars and contact bars.The stud |26 is held in the frame 40 (seeFigure 2).

The contact bar |5 is provided with only one set of springs |29,positioned to bias the contact end of the switch blades into engagementwith their corresponding conductor bar. The springs are held in place bythe usual spring clamp and stud arrangement similarly to Figures 1 and2, and engage in indented areas 2|. The springs are actuated by a cammember 32 operating through ball thrust members 39, as described inconnection with Figures 1 and 2. The cam member may be in the formshown, i. e., with two sets of cam surfaces as used in the previousform, so that it will be a standard part for both forms, and, obviously,it may also be designed to have only one set of cam surfaces toaccommodate one set of springs.

Theswitch blades at their hinge ends are held in constant pressureengagement with the conductor bar I2, and the contact ends of the switchblades are adapted, as in the previous form, to be brought into and outof pressure engagement with vthe conductor bar I4. Even though theswitch blades at their hinge ends are held in pressure engagement, thisfact does not materiallyhinder the opening and closing movements of theswitch.

Figure 14 shows the type of switch shown in Figure 5, but with the hingeend of the switch blades held in constant pressure engagement with theconductor bar 10 by an arrangement similar to that used in connectionwith the switch of Figure 12. Reference may be had to Figure 15 whichshows the manner in which the various parts of .the switch at the hingeend are assembled. 'I'he switch blades are providedwith annularindentedareas |30 formed in the outer sides thereof which result incorresponding ring projections |3| (see Figure 15) on the inner sides ofthe switch blades. Spring washers |32 with inturned flanges |34 fit intothe indented areas |3| and are adapted to bring the switch blades intopressure engagement with the conductor bar IIJ by means of nuts |35threaded onto stud |36 passing through the various parts.- It will beseen that the switch blades are held in constant pressure engagementwith the conductor bar, but, as stated in connection with Figure l2,this fact does not materially hinder the opening and closing movementsof the switch. The switch blades are provided with a single set ofsprings |37 for bringing the contact ends of the switch blades into andout of engagement with the conductor bar The arrangement of theremaining parts and the operation is as described in connection withFigure 5.

From the foregoing it will be seen that the arranged to' engage'theadjacentv ends of the switch y.blades individual thereto, a ball memberengaging the inner end of each of said lever members, and cam meansincluding a cam surface engaging each of said ball members and operatingtherethrough for moving the inner ends of said lever membersoutwardlyand thereby the outerends thereof inwardly to move the respective endsof said blade members into contact engagement with the switch membertherebetween.

4. Av switch comprising, a pair of stationary aligned spaced-apartplate-like switch members, a switchblade for interconnecting said switchmembers including-a pair of flexible blade members disposed on oppositesides of said switch members,l a pairfofv resilient lever memberspivinvention constitutes a simple device which has y the advantageousfeature of good electrical contact and can be operated with ease.

.While I have shown and described certain 'specific embodiments of theinvention, it is to be understood that the details are not limiting, butillustrative, and all arrangements of` parts to meet particularadaptations, and substitution of equivalents, shall be within the spiritand scope of the appended claims.

I claim:

1. A switch comprising, ay pair of stationary aligned spaced apartplate-like switch members, a switch blade for interconnecting saidswitch members including a pair of blade members disposed on oppositesides of said switch members, a pair of lever members pivotedintermediate their ends at positions spaced from the ends of said blademembers on the outer sides thereof with the outer ends of said switchmembers being arranged to engage the adjacent ends of the switch bladesindividual thereto, and means for moving the inner ends of said levermembers outwardly and thereby the outer Yends thereof inwardly to movethe respective ends of said blade members into Contact engagement withthe switch member therebetween. i

2. A switch comprising, a pair of stationary aligned spaced apartplate-like switch members, a switch blade for interconnecting saidswitch membersincluding a pair of blade members disposed on oppositesides of said switch members, a pair of lever members pivoted-intermediate their ends at positions spaced from the ends of said blademembers on the outer sides thereof with the outer ends of said switchmembers being arranged to engage the adjacent ends of the switch bladesindividual thereto, ball members engaging the inner ends of said levermembers, and cam means operating through said ballmembers for moving theinner ends of said lever members outwardly and thereby the outer endsthereofinwardly to move the respective ends of said blade members intocontact engagement with the switch member therebetween.

3. A switch comprising, a pair of stationary aligned spaced apartplate-like switch members, a switch blade for interconnecting saidswitch members including a pair of blade members disposed on oppositesides of said switch members, a pair of lever members pivotedintermediate their ends at positions spaced from the ends of said blademembers on the outer sides lthereof with the outer ends of said switchmembers being' otedgintermediate their ends at positions spaced from theends of said blade members on the outer sides thereof with-the outervends of said switch members being arranged to engage the adjacent endsIof the switch blades individual thereto, ball members engaging theinner ends of said resilient `,lever members, and cam means operatingthrough said ball members for moving the inner ends of said resilientlever members outwardly and thereby the outer ends thereof inwardly tomove therespective ends of said flexible blade members into contactengagement with the switch member therebetween.

A switch comprising, a pair of stationary aligned spaced apartplate-like switch members, a switch blade for interconnecting saidswitch members including a pair of blade members dis' posed on ,opposite`sides of said switch members. a pairfof lever members pivotedintermediate their ends at positions spaced from theV ends Vof saidblademembers 'on the outer sides thereof with the outer ends of saidswitch members being arranged to engage the adjacent ends of the switchblades individual thereto, andmeans for moving said `switch blade to andfrom switch closed position and as a movement sequential theretooperating said lever members to move the respective ends of said blademembers into and out of contact engagement with the switch membertherebetween.

6.*A switch comprising, a pair of stationary aligned spaced apartplate-like switch members, a switch blade pivoted on one of saidstationary switch members for interconnecting said switch membersincluding a pair of blade members disposed on opposite sides of saidswitch members, a pair of lever members pivoted intermediate their' endsat positions spaced from the ends of said blade members on' the outersides thereof with Athe outer ends of said switch members being arrangedto engage the adjacent ends of the switch blades individual thereto, andmeans for moving said switch blade to and from switch closed positionand as a movement sequential thereto operating said lever members tomove the respective ends of said blade members into and out of contactengagement with the switch member therebetween. s

7. A switch comprising, two pairs of stationary aligned spaced apartplate-like switch members, a switch blade for each pair of stationaryswitch members pivoted on one of said stationary switch members forinterconnecting its respective pair of switch members, each switch bladeincluding a pair of blade members disposed on opposite sides of itsrespective pair of switch members, a pair oflever members for each ofsaid blade membersand pivoted intermediate their ends at positionsvspaced from the endsof said blade members on the outer sides thereofwith the outer ends of said switch members being arranged to engage theadjacent ends of the switch blades individual thereto, and commonoperating means for moving said switch blades to and from switch closedposition and as a movement sequential thereto operating said levermembers to move the respective ends oflsaid blade members into and outof contact engagement with the switch member therebetween. s

8. A switch comprising, av pair of stationary aligned spaced apartplate-like switch members, a switch. blade pivoted on one of saidstationary switch members for interconnecting said switch membersincluding a pair of' blade members disposed on opposite sides ofsai'dswitch members, a pair of lever members` pivoted intermediate theirends at positions spaced from the ends of saidV blade members on theouter sides thereof' with the outer ends of said switch members beingarranged to engage the adjacent ends of the switch blades individual'thereto, and operating meanssupported between said'blade members foropening and closing the switch and for moving the inner ends of saidlever members outwardly and thereby the outer ends thereof inwardly tomovev the respective ends of said' blade members into contact engagementwith the switch member therebetween.

9. In a switch, a pair of stationary switch members, a switch blademovable into and out of engagement with said stationary switch members,lever means adapted to bear against said switch blade, cam means adaptedto operate said lever means and thereby bring said switch blade intohigh pressure engagement with said stationary switch members, andoperating means for operating said cam means to release the pres'- sureon said switch blade and'thereafter in a continuous: operation openingthe switch.

10l In a switch, a pair of stationary switch members, a switch blademovable into and' out of engagement with said stationary switch members,lever means adapted to bear against said switch blade, cam means adaptedto operate said lever means and thereby bring said switch blade into`high pressure engagement with said stationary switch members, andoperating means for closing' the switch and thereafter in a continuousoperation' operating said cam means to bring said switchblade into highpressure engagement with saidr stationary switch members.

11. In a switch, a pair of stationary switch members, a switch' bladecomprising a pair of blade members movablev into and out of engagementwith said. stationary switch members on opposite sides thereof,oppositely acting resilient means adapted to bear against said blademembers at each point of engagement with said stationary switch members,and cam meansl adapted` toreact between` oppositely acting resilientmeans and thereby bring said blade members into high pressure engagementwith said stationary switch members.

12. In` a switch, a pair of stationary switch members, aswitch bladecomprising a pair of said localized areas of contact, and cam meansadapted to react between said oppositely acting resilient means andthereby bring said localized areas of said blade members into highpressure engagement with said stationary switch members.

13. In a switch, stationary switch members, a switch blade movable intoand out of engagement with said stationary switch members, lever meansfor bringing said switch blade into high pressure engagementv with saidstationary switch members, cam means for operating said lever means, andoperating means initially moving in `a rectilinear path for operatingsaid cam means and as a continuation thereof in a circumferential pathfor opening the switch.

14. In a switch, stationary switch members, a switch blade movable intoand out of engagement with said stationary switch members, lever meansfor bringing said switch blade into high pressure engagement with saidstationary switch members, cam means for operating said lever means, andoperating means initially moving in a circumferential path for closingthe switch and as a continuation thereof moving in a rectilinear pathfor operating said cam means.

15. In a switch, stationary switch members, a switch blade movable intoand out of engagement with said stationary switch members, spring meanscarried by said switch blade and adapted to bear thereagainst forbringing the same into high pressure engagementA with said stationaryswitch members, cam means carried by said switch blade for operatingsaid spring means, and means carried by one of said stationary switchmembers for operating said cam means.

16. In a switch, stationary switch members, a switch blade movable intoand out of engagement with said stationary switch members, said switchblade comprising a pair of blade members one on either side of saidstationary switch members, oppositely acting spring means at each end ofsaid switch blade Ladapted to bias the ends of the blade members thereofinto engagement with their corresponding stationary switch members, cammeans carried between said blade members and adapted to operate saidspring means whereby its force is expended between oppositely actingspring means, and means for operating said cam means.

1'7. A switch comprising, a pair of stationary aligned spaced apartplate-like switch members,

a switch blade pivoted on one of said stationary switch members forinterconnecting said switch members including a pair of blade membersdisposed on opposite sides of said switch members, a

' pair of lever members pivoted intermediate their blade members oneoneither side of said station-` ary.y switch members pivoted for freerotation on one of said stationary switchY members and movableinto andout off engagement with the" other stationary switch member, each ofsaid blade members being,l provided with a localized areaof contact, atjeach end thereof, oppositely acting resilient means at each end'ofv saidswitch blade adapted to. bear against.. said blade members atl ends at aposition spaced from the closing end of said switch blade on the outersides thereof, the outer end of each of said lever members adapted toengage one of said blade members at its point of engagement with thestationary switch member individual thereto, ball members engaging theinner ends of said lever members, and cam means operatingthrough saidball members for moving the inner ends of said lever members outwardlyand thereby the, outer ends thereof inwardly to move the ends of saidblade members at the closing end of said switch blade into contactengagement with the switch member therebetween.

18. A switch comprising, two pairs of station- 4ary spaced apartplate-like switch members, a

switch blade, for each pair of stationary switch members pivoted on oneof said stationary switch members for interconnecting its respectivepair ofi switch members, each switch blade including a pair of blademembers disposed on opposite sides of its respective pair of switchmembers, a pair of lever members for each pair of said blade members andpivoted intermediate their ends at a position spaced from the closingend of said blade members on the outer sides thereof, each of said levermembers adapted to engage its respective blade member at its point ofengagement with the switch member individual thereto, and commonoperating means for moving said switch blades to and from switch closedposition and as a movement sequential thereto operating said levermembers to move said blade members at their closing end into and out ofengagement with the switch member therebetween.

19. A switch comprising, a pair of stationary aligned spaced apartplate-like switch members, a switch blade pivoted on one of saidstationary switch members for interconnecting said switch membersincluding a pair of blade members disposed on opposite sides of saidswitch members, a pair of lever members pivoted intermediate their endsat a position spaced from the closing end of said blade members on theouter sides thereof, said lever members adapted to engage theirrespective blade members at the closing end thereof to bias them intocontact engagement with the switch member therebetween, an arm adaptedto operate said lever members and to serve as a handle for opening andclosing the switch, and locking means for locking said arm againstoperation of said lever members during the closing movement of theswitch.

20. In a switch, a pair of switch members, a

switch blade movable into and out of engagement with said switchmembers, levers pivoted to act at the ends of said switch blade, an armpivoted on said switch blade and provided with spreader means, said armbeing adapted to operate said levers through said spreader means andthereby bring said switch blade into high pressure engagement with saidswitch members, said arm also serving as an actuator for opening andclosing the switch, and means for locking said arm against operation ofsaid levers during the closing movement of the switch.

21. In a switch, a pair of switch members, a switch blade movable intoand out of engagement with said switch members, levers pivoted to act atthe ends of said switch blade, an arm pivoted on said switch blade andprovided with spreader means, said arm being adapted to operate saidlevers through said spreader means and thereby bring said switch bladeinto high pressure engagement with said switch members, said arm alsoserving as an actuator for opening and closing the switch, means forlocking said arm against operation of said levers during the closingmovement of the switch, and stop means for releasing said locking meansat the end of the closing movement of the switch, after which continuedmovement of said arm will operate said levers.

22. In a switch, a pair of switch members, a switch blade movable intoand out of engagement with said switch members, levers pivoted to act atthe ends of said switch blade, an arm pivoted on said switch blade andprovided with spreader means, said arm being adapted to operate saidlevers through said spreader means when the switch is closed andthereby, through the outer ends of said levers, bring said switch bladeinto high pressure engagement with said switch members, said arm alsoserving as an actuator for opening the switch, and stop means on saidarm to check the movement thereof with respect to said switch bladeafter releasing the pressure on said switch blade, following whichcontinued movement of said arm will open the switch.

23. In a switch, a pair of switch members, a blade assembly comprisingblade elements movable into and out of engagement with said switchmembers, resilient levers mounted on said blade assembly with theirouter ends acting on the ends of said blade elements, thrust membersengaging the inner ends of said levers, an arm pivoted on said bladeassembly and provided with cam surfaces, said arm being adapted tooperate said levers through said cam surfaces and thrust members andthereby, through the outer ends of said levers, bring said bladeelements into high pressure engagement with said switch members, saidarm also serving as an actuator for opening and closing the switch, andmeans for locking said arm against operation of said levers during theclosing movement of the switch.

24. In a switch, switch members, a switch blade movable into and out ofengagement with said switch members, levers pivoted to exert pressure onthe ends of said switch blade, cams adapted to operate said levers andthereby bring the ends of said switch blade into high pressureengagement with said switch members, and means for operating said cams.

25. In a switch, switch members, a switch blade movable into and out ofengagement with said switch members, said switch blade comprising a pairof blade members disposed on opposite sides of said switch members,levers pivoted to apply pressure to the ends of said blade members,spreader means reacting between said levers for operating said leversand thereby bringing the ends of said blade members into high pressureengagement with said switch members, and means for operating saidspreader means.

26. In a switch, a pair of switch members, a switch blade pivoted on oneof said switch members and movable into and out ofr engagement with theother switch member, a lever pivoted to transmit pressure to the closingend of said switch blade, cam means adapted to operate said lever andthereby bring the closing end of said switch blade into high pressureengagement with its corresponding switch member, and means for operatingsaid cam means.

27. In a switch, a pair of stationary switch members, a switch bladepivoted on one of said switch members and movable into and out ofengagement with the other switch member, said switch blade comprising a.pair of blade members disposed on opposite sides of said switch members,oppositely acting resilient means adapted to exert pressure against saidblade members at the closing ends thereof, and cam means adapted toreact between said oppositely acting resilient means and thereby bringsaid blade members at the closing ends thereof into high pressureengagement with the corresponding switch member.

ELIAS S. CORNELL.

